For the "AS-Interface Basic" manual, see

https://support.industry.siemens.com/cs/ww/en/view/35016496

Note on security:

For plant networking, suitable protective measures (including IT security, e. g. network segmentation) must be taken to ensure safe operation of the plant. For more information on the topic of Industrial Security, see
http://www.siemens.com/industrialsecurity.

For the "AS-Interface Standard" manual, see

https://support.industry.siemens.com/cs/ww/en/view/38722160